Compression ratio control



Aug. 17, 1943. w. M. ALLlsoN COMPRESSION RATIO CONTROL Filed Feb. 24, 1941 4 Sheets-Sheet 1 ATTOR N EY WITNESSES W. M. ALLISON COMPRESSION RATIO CONTROL Filed Feb. 24, 1941 4 Sheets-Sheet 2 W s vL u R Oe Tn WM n o s u w ATTORN EYS Au9.,17,`A 1543.

4 Sheets-Sheet 4 K x N m `i .&`

w, M. ALLlsoN (AlrOMPRESSION RATIO CONTROL Flled Feb. 24, 1941 -rrmasslss BY ATTORNEYS HWeeL, the .purpose i 112151wallehownggtheipQStioning ofthe Of vthis inyeption :is 'tevv mressllwbyzvariation and to' prvidemeans used in; cohj limericn libere Wit 1F rotary motorQSuchaS is set forth and described center of the crank pin carrier, the center'off the crank pin, the connecting rod and the piston',

' shown in Figs. 3 and 4. Y The pumps are of the i Vspring pressure type adapted to 'maintain a conthe piston will have reached the point of furthest possible travel within'the cylinder. If the Synchronisation is changed so that. either the `cylinder assembly erV the crank pin 'carrier follows the other slightly, then at no time can a straight; line `be; drawn between the centerof the ilyWheeI, the crank pin and the connecting r0d,and the connecting rod will always have a certain angularity, as `shown in diagrammatic 1 -form in Ifig.` 14, and the point of furthest travel.

Y 1|. and plunger. T2.

of the piston within the cylinder will vbe changed.

Referring particularly to Eig. .14, wherein isy illustrated in full lines the-rrst position meni tioned, in which a straight line maybe drawn through the center of the crank pin carrier 25,

through the connecting rod and throughtl'iecen-V v A ter vof the cylinder, the piston 28 is shownV in its path Vof furthest travel vand the cembustion f chamber 3 'ljis'reduced. Where the synchronization is changed'so thatthegpqint 39j represents stant pressure and (are provided withV a cylinder A spring A13 maintains a constant pressure 'en the plunger. `The lower portion of the plunger l2 engages a link 'M'which isrfastened to the'rocker arm I5 pivoted at 'I6 to the post 11.! @The vother-'end 'l of the rocker arrn is-weighted and the Vroller 'Hl`v is mounted` thereon. As the roller l0 is engagedbythe high point 69 of the cam, the plunger is pulled' cutwardiy vinthe cylinder causing the suction of oil'through-the port 8U past the check Vvalve 8| into thegchamberZ lof thepump. The spring `'|3"will exert vpressure against 'the plunger to push it forwardly and to pass the oil through the port 83, check valve 84, into the port 85 leading to theduct 60. While the plunger is sucking in the crank pin 26, the position, of thepistonin its furthest point of trau/eras;ultimate,@1 bythe dottedflines, *and the combustion'A "chamber will "be larger, as shown Vbythe dotted lines A.j `Quite obviously, it will be possible to maintain thepresy Vvsure despite differences in :f atmospheric pressure,

by varying the-synchronization between thev crank pin carrierY and 'the"C ylinder'assfen`1l-nly` andl thus varying the compression ratio. For exam-y ple,V the motor is designedl-t'or operate 1atlower ,levels with the flywheel and cylinderj assembly so synchronized that thepistorxswuldjdene a Ylarge combustion chamber, andaslf higher altitudes and lower atmospheric pressure are encountered synchronization -would'be changedgsdthat oil the check valve'will prevent any'oil passing through' the port 85 into the chamber 82and oncev the presslulre"operation is` started the check valve 8| willprevent anyoil'- passing from'fthe chamber through the port au. `l f 'It will bejappreciatedjthat the pumpsV will maintain steady pressurek vand .that-Twhen, the

Vpressure built up in the ducts:is'- equ a1.to the Vpressure of the springfthe pumps will remain. lcharged and the,Y roller"lQwill'havexonly slight Contact withthe cam r69. The pumpswill then remain in Acharged position until'thejpressure in theducts fallsbelowj the. pressure of the spring when another pumping operationy will take place.

Y It will also `be; appreciated? 4that centrifugal the combustin 'chamber Vwc'uld V'be yreducedV to 1 Vtion tothe flywheel 'or crank pin carrier 25; the Y `mechanism hereinafter described provides a. sure,V

smothandsuitable control.- i Y As shown inFigs 1 and 6, the flywheel 25 is adapted to rotate about `the shaft Sland is `mounted (inthe bearing assembly'fixedto the cr'ankcase :4|.' vThe gear32 is provided with a.

seriesv of bosses 43 which extendV through' slots M inthe flywheel face cirtop. These bosses'engage a spider ring 45,a'ndma'y` be affixed thereto by belts.; rite spiderring 45V is provided with a series of'radially extending armslwhi'ch enm'aintainV thefsameV pressure. While the 'results described may be obtained by any means which;

gage and are ypivoted to connecting rodsf'l'land dersns l" and 52.

"Itivill'be Vappreciated that 4the movement ef the ypistons intlfieA cylinders, with the resultant action yon the spider ring'arms and spider ring, will vary ill8le`ading to pistons 149 Vand 50 Within thvcylinx Mounted on assembly l401s alcam .ring 68 having' high points 69 adapted toengage rellersl onthe pumpsglandlasthe flywheel -f2'5'rotateson the assembly. The pumpsrBZ Vand s A 61" arefidentical in structure, and are mostclearly thjedotted line infFigQ" j 1 ,1-Thegvalves 6| and -66 'aresimilarin operation,

and'an enlarged' view-thereof is jshownfinjFlg. 1.0. Y These valves are -controlledland operated 'by Yfa sleevepositione'daroun'd the bearingassembly-6&1 TheJsleevejfhasjhelical slots 9| :adapted to" engage pins-`92` en the bearing' as- 'rsembly 401s@ that 'mpv'emenf ofthe operating leverV 93 rotating' the: s leev''sfwillicause' it tc arm 99 shown-inFig force due nto f the rotatien Ywouldaffect theV rela,-Y tiv'e'weight of the moving 'partsofthe pumpgand inf order to equalizefthe 'pressure of the centrif'. uga] force'therweivght'l is. provided;

: 1 Due' toythe 'centrifugal' action o'fjthe ilywheel; the oil supplywithinl the `flywheel 251A 'will'be thrown against the wall |16: A p ort'l is provided ,to ,dispose'ofL excess il"vvhich'l should;J not rise and ifall onithefbearingassembly. 'The sleeve 90 Iis provided vvithftvvo` cairrlfaces-4 94 'and 95 Shaving high "p'c'ilrfrtsiSS andf-Slandrneeting atfa lowpcintSf Any suitable means, Vsuch as'r the and 2 engaging the vlevier 93 maybe usedtombvefthellever,

'- VThe valves 6l vand {i6-'are positioned at Ydifferent fieveis so that theftappets luc and 10| there@ are so placedthat whenthejtappet Illi'is oppo- :site-'thelow point 98 in the` sleeve 90 'the'tappet Y 2| 0| will engage the' high point; 'The valves themvalve 5|, and withthe 'duct' 5751111` the case ofthe seatY D4 adaptedto cooperate Withthe valve head |05.:vr f Thel valvestem 5 wpasses through `'a "chambery |01 having apor'tfl leading into theV interior ofth'e illywheel YV25,@ A spring |019 tends to keep thefvalv'e closed.

' VThe tappet |00 extendsthrougha posti: Fand interior of a geen l 3 'positioned in the post Y| pass sleeve has been preyiouslyfpointed ou I I5 in the head I I6 slidablymourlted initheipostf 'rhlsf will f 'sleeveglm isprovided.v @his sleeve mayLberivl, 320

valve 6B to close'.

pemflllbe provided' with; az-lefihanathfeaa.

isyopened. `the reSultantt-ur g of` the spider with its segments vIzji angl tappets. In actual lpraiie the tapp'etsfW-ill beuil-t so that there Will be afslig'fht cleararioejhe- 'Wi-ll adjust the flthelzgearlZ-f. J 5 V11111 a; rotary motor hayjillg. acylincl semhly mounted for rotationcylindesfin saidV l .eating wlthxsaldgl Y' Carrier for synchronizing. thejrotatioil' thereof,

and# ansforjlraryllg the 'patil'of trail/ e1 of said Ristori Y ingjljirl'eehallisfor'iaryillg' the relationheft eeh said cranlI/iin Carrier-fand fits' synchronizing et'edai .Ml @the lieti-emol me flywheel and provided f oif holding theuf'arzebf the'flywheelin oylil'icliar' assembly, pistonsj in aid]cyliritly angle to said Cylinder assembly; cozllfleting rods 'saldveyllnqers' said means 1Com ris'-V gear.

The i a having .geen moans on .Seieg and on sai chronizi i.

pinarrierj of mean fior Varyilig-`the compressleeve". Graduations' will therefore be "proyizlei f loindioaie to the pilot` illegale# position or While Yil; the

ank prin atari motor 'have control the operation of said valves.

. said gear,` arms on. said spider* ring, and means for exerting pressure fon theends of said arms to selectively position said.' gearwith relationfto said crank 'pin carrier.

. 6.1-The combination with arotaryimotor having. a cylinderr assembly anda crank pin carrier assembly andrcrank pin carrier controlling 'the synchronization`v thereof,V of means for varying the compression ratio of said motor, said"rneans carrier, .ag ca m ring'liaving high pointsmounted on saidbearing assembly adapted to engage the mechanismfof saidvpumpsto maintain pressure within said system, and a cam-facedsleeve slid- 55 ably mountedon said bearing assembly` to control '.saidyalves. Y r. l

Y 11. .In a motor of the class described, a crank pin carrier, a synchronizing gear Ymounted in `said crank pin carrienhydraulicmeans communicat- Vrfnount'ed for rotation at an angle toeaeh other, 10 ing withfsaid synchronizing gear to vary the poand engaginggear'means between saidcylinder sitionl of rsaid'gear. .with vrelation to said crank pin'. carrier, said hydraulicv means-including a pumpmounted within said crank pin Vcarrier and #adaptedto lmaintain pressure in 'said' system, an

Comprising spider ring'1 engaging weiss-nehm'. v15y operatingl'arm'on said pump, and-a cam'on said nizing gear on said crank'pincarrier; arr'nsfon 'said t spiderV ring; pistons and'l cylinders "engaging said arms,|f1uid ductsfeommunicating with said cylinders, pumpsand valves controlling the pasfcrankypinfcarrier mounting .adapted to engage saidoperating arm to operatesaid pumpk I 12. In a motor of the class described, a crank pin carrier, a synchronizing Agear mounted in the sage of uid through s dV ducts whereby :the 20 faceofsaidorank pinl'carrier and having a memposition of said pistons in said scylinders'mav be Varied to control the positicnoi saidgearl 'Il with relation to said crank pin carriere?.L L '7. In ardevice ofthe character described, a crankpin carrier, vslots in the face V of said crank pin carrier, a synchronizing gear, bosses on said synchronizing gear `engaging in said slots', a

"spider ring, arms on saidspider ring,.a pair o cylinders positioned adjacent ,theend ofeach I of said arms, pistons iin said cylinders, connect- 30 ing rods between eachfof said pistons and the end of said arms, fluid ducts leading to each vof `said cylinders, a cani-operatedA pump foreach of said fluid ducts. adapted to maintain pressure in said'ducts, a Valve foreach of said iluid ducts adapted to lower the pressure of said ducts, tappets on each of said valves, and afcamfaced sleeve adapted .to engage said tappets and to v8. In adevic e of the character described, a valve; a stem on said valve, a head engaging saidstem, a tappet, a. threaded end Von 'said tappet,`

to openV saidfvalvetand means engagingsaid Y gearmember tocause said tappettoscrewfinto .said head'to allow said vvalve to c lose..fv Y

9. In a rotary motor'of the type described, a

crank pin .carrier mounted for rotation on: ajh

. bearing assembly, fa synchronizing gear on the facerof saidvcrank pincarrier, aA memberv Within..

,Said Carrier. en ggngf Sai@ gear. if hydraulic: 55 ofsaid valves andpumps adapted tofneutralize system including cylinders, pistons, pumps and valves cooperating with said member to'vary the .position of saidmember-with relation to said crank pin carrier, a sleeve `having camgfac'es slidablyY mounted on saidbearing assembly Vand Asition of said gear withrelationfto saidcrank-6 `pin carrier.` 1 Y 10.` In a mO'OrjjOf VVthe class Ydescribed,Yafcranlr pin carrier mounted Afor-rotation on aY bearing-assembly, aV synchronizing gearadjustably mounted 4 onjth'e face of said crankpin carrier and 'having :70 ingengaging said slots, whereby the rotation of a member extending .within s'aidjcrank-pin carrier, anv hydraulic system VincludingY cylinders, pistons, pumps and -valves Y. engaging -s`aid member adapted to movesaid member to -vary the posil er extendingv into the interior thereof-,hydraulic lmeans engaging vsaid member and adapted to Vary the position of said -gear withrelation to said crank pin{;ca rrier, a sleeve positioned in the 2.5 mountingofsaidcrank pincarrier and having carnmed faces, a pairofrvalves in said hydraulic system Ypositioned with their operating mechanism Y to contact said sleeve,whereby-themovement of eration of said valves. f

v13.'A device asset forth in. claim12, in which each of said valves-isprovided with a tappet, a head having a threaded portion, a threadedend on said tappetsadapted toengagesaid .threaded .35 portions, splines Onsaidtappetsa gear's'urrounding each tappet'engaging Vsaid splinesysegments onsaid Imember'engaging said gears, whereby the movement ofV said sleeveywill'force one ofsaid izalDpe-ts` inwardly to open vits-valve and operate 40 said'hydraulic lsystemeausing saidv member torotate and causing onefofsaid.tappetsto screw into itshead ,toallow itsvalve to close,V and the other of `said tappets to unscrewfromf its headso that said tappet remains in operative position with 45 relationfto saidjsleevey.r V- I Y l 14. In a rotary motor cf the cl ass described, a

crank pin carrier, a :synchronizing gear mounted 'on said .crank pin carrier-and having a` member extending .into said crank pin-carrier, an hy- 5o draulic systemiengaging said'member and Aadapted V.to-move said memberto selectively-position said gear with relation to said: crankpin carrier, said hydraulic system-including cylinders, pistons,

. valvesand pumps, and weighted members on each carrier, hydraulic u means cooperating with said member Yfor. varying thefposition 4of ysaid. .gear withrelation to said crank pin carrier,l said hy- 5 ldraulic means ineluding'cylinders, pistons; pumps -and valves, a cam-j facedsleeve positioned on the mounting of said Crankjpin carrier andfadapted Y Vto engage the operating` mechanism of saidvalves,

v.helical slots'vinsaid sleeve-pins onsaidV mountsaidsleeve on said mountingwill cause-saidsleeve to riseor .fall longitudinally on said mountingl to present diiierent portions ofy said cam faceto-said operating mechanism ofjsadfvalves. v Ation of said gear with relation toV said crank pin W. M. ALLISON.

said sleeve on said mounting will control the op- 

